Heat exchangers



March 1959 w. A. WARRINGTON, JR 2, 7

HEAT EXCHANGERS Filed Sept. 12, 1957 x 2 Sheets-Sheet 2 INVENTOR,William A. Wa'rr/hgfon, Jr.

HEAT EXCHANGERS William A. Warrington, in, Cordova, Tenn.

Application September 12, 1957, Serial No. 683,531

Claims. (Cl. 2S7-39) This invention relates to certain new and usefulimprovements in heat exchangers, and particularly relates to heatexchanging means which are adapted-for utilization in refrigerating orcooling units, as of the type of home air conditioning units, for thepurpose of cooling and condensing the refrigerant to provide for itsrecirculation through the system and its utilization during suchrecirculation for the purpose of heat absorption to effect cooling ofsurrounding areas. Numerous types of refrigerants are employed insystems of this sort, such as, for example, halogenated hydrocarbons andother suitable refrigerants. in such systems the refrigerant passes froman area cooling means, such as a conventional coil, into a compressor ingaseous condition, at which time it is at a relativelyhigh'ternperature. It is passed thence from the compressor into arefrigerant cooling heat exchanger in which the heat carried by therefrigerant is dissipated, with the result that the gaseousrefrigerantis condensed and returned to substantially liquid stage, inwhich conditionit is ultimately passed into the cooling coil where it isbrought back to a gaseous state in the coil, absorbing the surroundingheat in the process of passing from the. liquified to the gaseous state.

The present device provides a new and novel improvement in the coolingheat exchangers such as are used in a system of the general type justdescribed.

The principal object of the present invention is to provide a new andnovel heat exchanging means, particularly adapted for effecting coolingand condensing of gaseous refrigerants in a cooling system, such as anair conditioning device.

A further object of the invention is to provide such heat exchangingmeans which comprises a bank of relatively enlarged elongated conduitsarranged in staggered position fore and aft, disposed for impingement bycool--.

ing air drawn thereover, with each of the conduits being providedinternally with an air flow tube for the passage,

of cooling air longitudinally through the interior of the conduit,whereby the refrigerant is disposed in a thin substantially annularlayer extending from end to end of the conduit, with large areaheat-radiating surfaces comprising the exterior of the conduit, and theinteriorof the air tubes effecting delivery of the cooling of impingingair to the thin annular layer of refrigerant.

A further object of the invention is to provide in such a device whichcomprises a plurality of interconnected refrigerant'conduits andinternal air cooling tubes projected through such conduits, theimprovement which comprises disposing the internal air cooling tubes ina position inclined from end to end relative to the refrigerant conduitwhereby to vary the dispostion of the refrigerant passing through thethin layer conduit.

A further object of the invention is to provide in such a device whichcomprises a pair of conduit tiers with the conduits disposed instaggered relationship, and means for delivering hot refrigerant to therespective tiers simultaneously, means interconnecting the conduits ofthe upper portions of each of the tiers, means interconnecting 2,877,991Patented -M-ar. 17, 19579 ice.

1 tubes projecting through the interior of such conduits,

with a spirally disposed baffle incorporated within the air coolingtubes whereby to impart a turbulence to the cooling air drawn throughsuch cooling tubes; and

A further object of the invention is generallyto improve the design,construction and efficiency of heat exchanging means.

Other and further objects of the invention will become apparent fro-mthe annexed specification.

The means by which the foregoing and other objects of the presentinvention are accomplished and the manner of their accomplishment willbe readily understood from the following specification upon referenceto-the accompanying drawings, in which:

Fig. 1 is a somewhat "schematic sectional plan view on a reduced scaleof an installation embodying the present invention.

Fig. 2 is an enlarged fragmentary sectional view taken as on the line11-11 of Pig. 1 from the rear of the heat exchanging means of thepresent invention.

Fig. 3' is a fragmentary, sectional elevational view takenas on the lineIlllll of Fig. 2.

Fig. 4 isv a longitudinal sectional view taken 'as on th longitudinalmidline of a typical conduit and air cooling tube contained therein.

Fig. 5 is a fragmentary cross-sectional view taken as on the line V-V ofFig. 2 on an enlarged scale.

' Fig. 6 is a view similar to Fig. 5 taken as on the line VlVl of Fig.2; and

Fig. 7 is a view similar to Fig. 5 taken as on the line Vil -VII of Fig.2.

Referring now to the drawings in which the various parts areindicated bynumerals, the present invention is adapted to be incorporated in asubstantially conventional system such as is shown schematically inFig. 1. As there shown, the invention comprises a substantially boxlikehousing 11 within which is mounted, in manner hereinafter to bedescribed, the heat exchanging means of the present invention, and whichincludes a rearwardly discharging centrifugal fan 13, preferably drivenby a conventional motor 15. The heat exchanging means includesspecifically a conduit bank 17 comprising a double tier of conduitsdisposed forward of fan 13 from which refrigerant condensate isdelivered as by piping 19 to a receiver 21, from which the condensate isdelivered by piping 23 to one end of a cooling coil 25, the opposite endof the cooling coil 25 being connected to a compressor 27, and thecompressor 27 being connected as by pipe 29 to a T-connection 31with-the conduit bank 17. be understood that the various componentswhich have just been referred to may be arranged in other dispositionsthan that which is shown in Fig. 1, and that the showing there isprimarily intended for a schematic illustration of a general system ofthe type in which the present invention is particularly useful.

Housing 11 includes a top 33, a bottom 34, and opfastened at one endtoside. wall 35"of thehousing, and at its opposite end is fastened tothe inner edge of a minor It will interior of the conduit at its lowerfront wall section 38. A supporting plate 39 comprising an uprightsubstantially vertical plate is disposed parallel to and spaced inwardlyfrom side wall 36. Spanning between the forward edge of plate 39, andthe forward edge of side wall 36, is a minor front wall section 38.Similarly spaced inwardly from side wall 35 is an additional supportingplate 43, which is a'substantially vertical dis posed element and ispositioned parallel to supporting plate 39 as well as parallel to sidewall 35. Plates 39, 43 are of substantially the same size.

To the rearward edge of supporting plate 43, a partition 45 is connectedand spans therefrom substantially parallel to screen 37 into contact andconnection with side wall 35. Each of the plates 39, 43 and partition 45are as stated, vertically disposed members and extend from housing top33 to bottom 34. It will be seen that partition 45, plate 43 and theforward section of side wall 35 define a chamber 47, which is covered atits front by a side section of screen 37 so that air may flow into thechamber but is blocked from flowing rearwardly beyond the chamber byside wall 35, plate 43 and partition 45. It will additionally beobserved that, while air may flow freely through screen 37, air isblocked from front to rear flow of housing 11 at the minor section frontwall 38, but that rearwardly of front wall 38 the space between plate 39and side wall 36 is unobstructed. Additionally, housing 11 is providedwith a rear wall 49 which is apertured to provide a rearward dischargeport for fan 13.

Mounted in and supported by plates 39, 43, are the elements comprisingconduit bank 17. Conduit bank 17 comprises, as heretofore stated, adouble tier of conduits 51, the conduits 51 being supported insubstantially parallel relationship, being horizontally disposed andvertically spaced apart. Preferably the tiers are arranged, as bestshown in Fig. 3, with one tier of conduits 51 disposed adjacent screen37,'being disposed horizontally and vertically spaced apart, and withthe other tier of conduits 51beingsimilarl'y disposed in horizontal,parallel and vertically spaced apart relationship, but in staggeredrelationship relative to the forward tier and being disposed rearwardthereof, with the conduits 51 of the rearward tier being respectivelypositioned rearward of a vertical space between two of the conduits 51of the forward tier. The lowermostconduit51 of the rearward tier ispositioned below the lowermost conduit 51 of the forward tier and ispositioned to intercept the space between the lowermost forward conduit51 and bottom 34. Each of conduits ,51 is a hollow pipe-like member andeach conduit is provided an airflow tube 53 which extends from end toend through the hollow interior of its related conduit, tubes 53 beingrespectively of a length in excess of the length of their relatedconduits so that the opposite ends of tubes 53 project laterallyoutwardly beyond the ends of conduits 51. Each of the tubes 53 is ahollow pipe-like tube of a diameter somewhat less than the diameterofconduits 51, and the tubes 53 are open at their opposite ends.

In the preferred embodiment of the present invention each tube'53 isinclined relative to its conduit 51 so that the tube is in contact withthe interior of conduit 51 at the upper portion at one end, and is incontact with the portion at the opposite end thereof. At their oppositeends, conduits 51 are rerespectively sealed to their related air tubes53 effectively closing off the ends of the interior space withinconduits 51. As stated, the opposite ends of air tubes 53 respectivelyprojectbeyond the opposite ends of their related conduits 51, and at oneend of the conduit bank, the open ends of tubes 53 project into chamber47, while the opposite open ends of tubes 53 project into the spacebetween plate 39 and side wall 36. It will be seen, as best shown inFig. 4, that the inclined disposition of the air tubes relative to theconduits is such as to provide a major portion of the interior space atthe upper portion of the conduit adjacent one end thereof, and a majorportion of the 4. interior space at the lower portion thereof at itsopposite end. The opposite legs of T-connector 31 communicate into theupper enlarged space at one end of the uppermost conduits 51, as shownin Figs. 2 and 3. Throughout the upper section of each of the tiers ofconduits 51 the enlarged spaces are interconnected by communicators 55which comprise short pipe-like section communicating the interiors ofadjacent conduits.

It will be observed that the inclined disposition of the respective airtubes relative to the conduits is alternated, that is to say, the airtube within the uppermost conduit is downwardly inclined from left toright, that in the next adjacent conduit is downwardly inclinedoppositely, that l is, from right to left, and so on alternatelythroughout the respective tiers of conduits 51.

At the lower extremity of the upper section of conduits 51 in each tier,which upper section preferably includes one-half the conduits in thetier, it is found desirable to effect a flow cross-over so as tointerchange the flow through the upper section of one conduit tier intothe lower section of the other conduit tier. Preferably, this cross-overis effected by diagonally disposed communicators 57, 58, cross-over pipe57 extending between the lowermost pipe of the upper section of forwardconduit tier and the upper conduit of the lower section of the rearwardconduit tier, as best shown in Fig. 2, it being observed that in thepreferred embodiment these conduits are respectively extended as at 51Aand so as to accommodate conveniently the reception of cross-over pipe57. Cross-over pipe 58 connects the upper section of the rearward tierof conduits with the lower section of the forwardmost tier of conduitsin similar manner, although,

as shown in Fig. 2, it is convenient that this connection be effectedinward of supporting plate 43 and does not require any alteration orextension of the conduits. It will be understood that, while theextension of the two intermediate conduits, as at 51A, is convenient andis I preferred, the interconnection between these conduits may be madewithin the bank of conduits in manner similar to that accomplished bypipe 58.

It is preferred that each of the air tubes 53 be provided with aspiralled vane 59, as best shown in Fig. 4, for the purpose of impartinga turbulence and spiralling rotation to air fiow through the respectiveairflow tubes. Rearward of conduit bank 17, a series of air directionalbafiles are provided. Preferably these include an upper baflie 61depending from top 33 and terminating in a rearwardly diagonalled lowersection which projects approximately to overlap the uppermost conduit ofthe rearward bank, a lower baflie 63 which similarly projects upwardlyfrom bottom 34 includes a rearwardly diagonalled portion which overlapsthe lowermost conduit of the rearward tier, and intermediate V-shapedbaflies 65 which are respectively disposed with their spaces inalinement with the spacings between the rearward tier of conduits 51.

In the operation of the device incorporating the present invention, thehot refrigerant is fed through pipe 29 to T-connection 31 and thence tothe uppermost conduits 51 of the forward and rearward tiers. Therefrigerant thus flows into the maximum upper space at the ends of theuppermost conduits 51 and passes into the annular space between theinterior of conduit 51 and air tube 53. As can readily be seen, thisdisperses the refrigerant into a thin annular layer surrounded on theoutside by the conduit 51 and contained on the inside by the air tube53. The refrigerant flows from the intake end of the conduit toward theopposite end, and due to the inclination of the air tube 53 relative tothe conduit within which it is contained, a change in the contour of thelayer of refrig erant is accomplished, resulting in a certain amount ofturbulence and mixing in the flow of the refrigerant as it passes fromend to end of the conduit and in generally improving the mixing of therefrigerant within the conduit as it flows from end to end. When itreaches the opposite end of the conduit it is discharged therefromsis-meatthrough communicator 55 into the next subjacent conduit in whichthe air tube is oppositely inclined so that the discharging refrigerantdischarges into the maximum up per space formed in the end of theconduit 51 and passes therefrom along the conduit, with the inclinationof the air tube effecting similar turbulence and resulting in dischargeof the refrigerant from the opposite end. The refrigerant follows thistortuouspathway from end to opposite end of the respective conduitsthroughout the upper section of the respective tiers.

When the refrigerant has reached the lowermost tube of the upper sectionof the conduits, in the preferred embodiment of the invention, as hereshown, it is desirable that the refrigerant from the forwardmost tier ofconduits be crossed over to pass into the conduits of the rearmost tier,and conversely that the refrigerant from the upper section of therearmost tier of conduits be crossed over to pass into the lower sectionof the forwardmost conduits. Such cross-over is accomplished by thediagonal pipes 57, 58, respectively communicating the upper section ofthe forward tier with the lower section of the rearward tier, and theupper section of the rearward tier with the lower section of the forwardtier.

While this refrigerant flow is in progress, motor 15 is activated todrive fan 13, drawing air through screen 37, and discharging samerearwardly through the port provided in rear wall 49. The air drawnthrough screen 37 impinges directly upon the exterior of the forwardmosttier of conduits 51, passes through the vertical spaces between theforwardmost tier of conduits, and impinges against the rearmost tier ofconduits. Baffles 61, 63, 65, disposed rearwardly of the rear tier ofconduits, are effective to direct the air so as to require the same topass substantially around the rearmost conduits in flowing therefrom,and the air drawn therethrough flows between the baffles 61, 63, 65rearwardly to discharge as indicated by the arrows in Fig. 1. Thecross-over between the forward and rearward tiers'of conduits, asheretofore described, is effective to more nearly equalize the coolingeffect of the air which is passed over the exterior of conduits 51 uponthe refrigerant contained in a thin layer therein. It will be seen thatas the air passes over the conduits of the forward tier it is somewhatwarmed before it impinges upon the conduits of the rearward tier.Consequently, the refrigerant is transferred from the rearward tier tothe forward tier, and conversely from the forward tier to the rearwardtier, in order that the refrigerant as it passes through the entire tierwill be subjected to a substantially equal amount of cooling air.

During the same operation, air is also drawn in through screen 37 intochamber 47 and passes through the open ends of air tubes 53 projectinginto the chamber 47, being withdrawn therefrom at the opposite open endsof the tubes in the space between plate 39 and side wall 36. As canreadily be seen, the cooling air is thus passed through the-internal airflow tubes 53 and provides a large surface cooling area against theinterior of the thin annular layer of refrigerant passing through therespective conduits 51. The spiralled vanes 59 with which each of theair tubes 53 is provided is preferred in order to provide a riftingrotation and consequent mixing of the cooling air as the same flowsthrough the air tube, resulting in a greater enhancement of the coolingeffect on the interior of the refrigerant layer.

It will be seen that by the device of the present invention the hotrefrigerant is transmitted through the conduit bank in a thin annularlayer which is subjected to a relatively large radiation surface on theexterior in the form of conduits 51, and to a relatively large radiationsurface on the interior in the form of the air flow tubes 53. As aresult, the efliciency of the device in effectively cooling therefrigerant is greatly enhanced and eliminates the necessity of spiralbathing or other heat radiating fins which have been considerednecessary in coils or other air cooled devices which are presently incommercial usage. After the refrigerant has completed its flow throughthe respective tiers of conduits it passes into piping 19, from which itis delivered to receiver 21 for recirculation through thesystem asheretofore described.

I claim:

1. Heat exchanger means adapted for use in a cooling system whichincludes means for circulating a fluid refrigerant to and from said heatexchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing,v

wall means cutting off air flow at one side of said open end, and airflow impeller means disposed to establish air flow in through said openend and out through said discharge; said heat exchanger means comprisinga conduit bank disposed in the path of said air flow,v said conduit bankincluding an upright forward tier of conduits and an upright rearwardtier of conduits, each said tier comprising a plurality of substantiallyhorizontal cylindrical rerfigerant conduits vertically spaced apart withthe conduits of the rearward tier intercepting spaces between andadjacent the conduits of the forward tier, each tier including an upperconduit section and a lower conduit section, a plurality of hollow, openended cylindrical air flow tubes, each said conduit having an air flowtube projecting through the interior of the conduit to define a thin,annular conduit space for the passage of refrigerant in a thin annularlayer through said conduits, said air tubes being respectively of alength greater than the length of the conduits related thereto and beingpositioned with their opposite open ends ex tending outwardly beyond theends of said conduits, each said air tube relative to its relatedconduit being inclined from contact with the upper portion of theconduit at one end to contact with the lower portion of the conduit atthe opposite end, to provide said annular space with a constantly variedcont-our from end to end of said conduit having a maximum lower space atone end and a maximum upper space at the other end, alternate conduitsand tubes in each said tier being positioned with said tubes oppositelyinclined, said conduit ends being sealed to said air tubes, meansconnecting said circulating means with the uppermost conduit of eachtier at the maximum upper space therein, means successivelyinterconnecting the maximum spaces of adjacent conduits in said tierupper sections, cross-over means communicating the lowermost conduit ofeach upper tier section with the uppermost conduit of each lower sectionof the other tier to transfer flow from one tier to the other, uprightplates at one end of said tiers segregating a portion of said housingopen end, one of said plates engaging said tiers outwardly from the endsof the majority of said conduits and inwardly from the ends of saidtubes with said tube ends projecting into said segregated portion,additional plate means adjacent the opposite end of said tiers connectedwith said wall means and engaging said tiers outwardly from the otherend of said conduits and inwardly from the other ends of said tubes withsaid tube other ends projecting'beyond said additional plate, saidplates directing air flow through said tubes, whereby to provide atortuous pathway for a thin annular layer of refrigerant betweenrelatively large external and internal heat radiating surfaces subjectedto the cooling effect of said air flow.

2. Heat exchanger means adapted for use in a cooling system whichincludes means for circulating a fluid refrigerant to and from said heatexchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing, wall meanscutting off air flow through one side of said open end, and air flowimpeller means disposed to establish air flow in through said open endand out through said discharge; said heat exchanger means comprising aconduit bank disposed in the path of said air flow, said conduit bankincluding an upright forward tier of aa zfaear.

interior of the conduit to define a thin, annular con-.

duit space for the passage of refrigerant in a thin annular layerthrough said conduits, said air tubes being respectively of a lengthgreater than the length of the conduits related thereto and beingpositioned with their opposite open ends extending outwardly beyond theends of said conduits, each said air tube relative to its re latedconduit being inclined from contact with the upper portion of theconduit at one end to contact with the lower portion of the conduit atthe opposite end, to provide said annular space with a constantly variedcontour from end to end of said conduit having a maximum lower space atone end and a maximum upper space at the other end, alternate conduitsand tubes in each said tier being positioned with said tubes oppositelyinclined, said conduit ends being sealed to said air tubes, meansconnecting said circulating means with the uppermost conduit of eachtier at the maximum upper space therein, means successivelyinterconnecting the maximum spaces of adjacent conduits, plate meanslocated at the opposite side of said open housing end defining a chamber, the open tube ends at one end of said tiers extending into saidchamber and the open tube ends at the oppo site end of said tiersextending behind said wall means, for directing air flow through saidtubes, whereby to provide a tortuous pathway for a thin annular layer ofrefrigerant between relatively large external and internal heatradiating surfaces subjected to the cooling effect of said air flow.

3. Heat exchanger means adapted for use in a cooling system whichincludes means for circulating a fluid refrigerant to and from said heatexchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing, wall meanscutting ofi air flow through one side of said open end, and air flowimpeller means disposed to establish air flow in through said open endand out through said discharge; said heat exchanger means comprising aconduit bank disposed in the path of said air fiow, said conduit bankincluding an upright forward tier of conduits and an upright rearwardtier of conduits, each said tier comprising a plurality of substantiallyhorizontal refrigerant conduits vertically spaced apart with theconduits of the rearward tier intercepting spaces between and adjacentthe conduits of the forward tier, each tier including an upper conduitsection and a lower conduit section, a plurality of hollow, open endedair flow tubes, each said conduit having an air flow tube projectingthrough the interior of the conduit to define a thin, annular conduitspace for the passage of refrigerant in a thin annular layer throughsaid conduits, said air tubes being respectively of a length greaterthan the length of the conduits related thereto and being positionedwith their opposite open ends extending outwardly beyond the ends ofsaid conduits, said conduit ends being sealed to said air tubes, meansconnecting said circulating means with the uppermost conduit of eachtier, means successively interconnecting the adjacent conduits in saidtier upper sections, cross-over means communicating the lowermostconduit of each upper tier section with the uppermost conduit of eachlower section of the other tier to transfer fiow from one tier to theother, plate means located at the opposite side of said open housing enddefining a chamber, the open tube ends at one end of said tiersextending into said chamber and the open tube ends at the opposite endof said tiers extending behind said wall means, for directing air flowthrough said tubes, whereby to provide a tortuous pathway for a thinannular layer of refrigerant between relatively large external andinternal heat, radiating surfaces subjected to the cooling effect ofsaid i 4. Heat exchanger means adapted for use in a cooling system whichincludes means for circulating a fluid refrigerant to and from said heatexchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing, wall meanscutting off air flow through one side of said open end, and air flowimpeller means disposed to establish air flow in through said open endand out through said discharge; said heat exchanger means comprising aconduit bank disposed in the path of said air flow, said conduit bankincluding an upright forward tier of conduits the passageof refrigerantin a thin annular layer through I said conduits, said air tubes beingrespectively of a length greater than the length of the conduits relatedthereto and being positioned with their opposite open ends extendingoutwardly beyond the ends of said conduits, said I conduit ends beingsealed to said air tubes, means connecting said circulating means withthe uppermost conduit of each tier, means successively interconnectingadjacent conduits, plate means located at the opposite side of said openhousing end defining a chamber, the open tube ends at one end of saidtiers extending into said chamber and the open tube ends at the oppositeend of said tiers extending behind said wall means, for directing airflow through said tubes, whereby to provide a tortuous pathway for athin annular layer of refrigerant between relatively large external andinternal heat radiating surfaces subjected to the cooling elfect of saidair flow.

5. Heat exchanger means adapted for use in a cooling system whichincludes means for circulating a fluid refrigerant to and from said heatexchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing, wall meanscutting off air flow through one side of said open I end, and air flowimpeller means disposed to establish air flow in through said open endand out through said discharge; said heat exchanger means comprising aconduit bank disposed in the path of said air flow, said conduit bankincluding an upright forward tier of conduits and an upright rearwardtier of conduits, each said tier comprising a plurality of substantiallyhorizontal refrigerant conduits vertically spaced apart with theconduits of the rearward tier intercepting spaces between and adjacentthe conduits of the forward tier, a plurality of hollow, open ended airflow tubes, each said conduit having an air flow tube projecting throughthe interior of the conduit to define a thin, annular conduit space forthe passage of refrigerant in a thin annular layer through saidconduits, said air tubes being respectively of a length greater than thelength of the conduits related thereto and being positioned with theiropposite open ends extending outwardly beyond the ends of said conduits,said conduit ends being sealed to said air tubes, means connecting saidcirculating means with the uppermost conduit of each tier, meanssuccessively interconnecting adjacent conduits, plate means located atthe opposite side of said open housing end defining a chamber, the opentube ends at one end of said tiers extending into said chamber and theopen tube ends at the opposite end of said tiers extending behind saidwall means, for directing air flow through said tubes, and spirallytwisted vanes mounted in said tubes for imparting rotation to air flowthrough said tubes, whereby to provide a tortuous pathway for a thinannular layer of refrigerant between relatively large external internalheat radiating. surfaces subjected to the cooling effect of said airflow.

6. Heat exchanger means adapted for use in a cooling system whichincludes means for circulating a fluid refrigerant to and from said heatexchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing, wall meanscutting off air flow through one side of said open end, and air flowimpeller means disposed to establish air flow in through said open endand out through said discharge; said heat exchanger means comprising anupright tier of conduits disposed in the path of said air flow, saidtier comprising a plurality of substantially horizontal refrigerantconduits vertically spaced apart, a plurality of hollow, open ended airflow tubes, each said conduit having an air flow tube projecting.through the interior of the conduit to define a thin, annular conduitspace for the passage of refrigerant in a thin annular layer throughsaid conduits, said air tubes being respectively of a length greaterthanthe length of the conduits related thereto and being positioned withtheir opposite open ends extending outwardly'beyondthe ends of saidconduits, each said air tube relative to its related conduit beinginclined from contact with the upper portion of the conduit at one endto contactwith the lower portion of the conduit at the opposite end, toprovide said annular space with a constantly varied contour from end toend of said conduit having a maximum lower space at one end and amaximum upper space at the other end, alternate conduits and tubes insaid tier being positioned with said tubes oppositely inclined, saidconduit ends being sealed to said air tubes, means connecting saidcirculating means with the uppermost conduit of said tier at the maximumupper space therein, means successively interconnecting the maximumspaces of adjacent conduits in said tier, plate means located at theopposite side of said open housing end defining a chamber, the open tubeends at one end of said tiers extending into said chamber and the opentube ends at the opposite end of said tiers extending behind said wallmeans, for directing air flow through said tubes, and spirally twistedvanes mounted in said tubes for imparting rotation to air flow throughsaid tubes, whereby to provide a tortuous pathway for a thin annularlayer of refrigerant between relatively large external and internal heatradiating surfaces subjected to the cooling effect of said air flow.

7. Heat exchanger means adapted for use in a cooling system whichincludes means for circulating a fluid re frigerant to and from saidheat exchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing, wall meanscutting off air flow through one side of said open end, and air flowimpeller means disposed to establish air flow in through said open endand out through said discharge; said heat exchanger means comprising anupright tier of conduits disposed in the path of said air flow, saidtier comprising a plurality of substantially horizontal refrigerantconduits vertically spaced apart, a plurality of hollow, open ended airflow tubes, each said conduit having an air flow tube projecting throughthe interior of the conduit to define a thin, annular conduit space forthe passage of refrigerant in a thin annular layer through saidconduits, said air tubes being respectively of a length greater than thelength of the conduits related thereto and being positioned with theiropposite open ends extending outwardly beyond the ends of said conduits,each said air tube relative to its related conduit being inclined fromcontact with the upper portion of the conduit at one end to contact withthe lower portion of the conduit at the opposite end, to provide saidannular space with a. constantly varied contour from end to end of saidconduit having a maximum lower space at one end and a maximum upperspace at the other end, alternate conduits and tubes in said tier beingpositioned with said tubes oppositely inclined, said conduit ends beingsealed to said air tubes,means connecting said circulating. means-2 withthe uppermost conduit of said tier at the maximum upper space therein,means successively interconnecting the maximum spaces of adjacentconduits in said tier," plate means located at the opposite side of saidopenv housing end defining a chamber, the open tube ends at one end ofsaid tiers extending into said chamber and the open tube ends at theopposite end of said tiers extending 'behind said wall means, fordirecting air flow through said tubes, whereby to provide atortuous'path' way for a thin annular layer of refrigerant between rela'tively large external and internal heat radiating surfaces subjected tothe cooling effect of said air flow.

8. Heat exchanger means adapted for use in a cooling.

system which includes means for circulating a fluid refrigerant to andfrom said heat exchanger means, a housing open at one end for air flowinto said housing, and

having an air flow discharge from said housing, wall} means cutting offair flow through one sideof said open end, and air fiow impeller meansdisposed to establish horizontal refrigerant conduits vertically spacedapart,-

a plurality of hollow, open ended air flow tubes, each said conduithaving an air flow tube projecting through the interior of the conduitto define a thin, annular conduit space for the passage of refrigerantin a thin annular layer through said conduits, said air tubes beingrespectively of a length greater than the length of the conduits relatedthereto and being positioned with their opposite open ends extendingoutwardly beyond the ends of said conduits, said conduit ends beingsealed to said air tubes, means connecting said circulating means withthe uppermost conduit of said tier, means successively interconnectingadjacent conduits in said tier, plate means located at the opposite sideof said open housing end defining a chamber, the open tube ends at oneend of said tiers extending into said chamber and the open tube ends atthe opposite end of said tiers extending behind said wall means, fordirecting air fiow through said tubes, whereby to provide a tortuouspathway for a thin annular layer of refrigerant between relatively largeexternal and internal heat radiating surfaces subjected to the coolingeffect of said air flow.

9. Heat exchanger means adapted for use in a cooling system whichincludes means for circulating a fluid refrigerant to and from said heatexchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing, wall meanscutting off air flow through one side of said open end, and air flowimpeller means disposed to establish air flow in through said open endand out through said discharge; said heat exchanger means comprising anupright tier of conduits disposed in the path of said air flow, saidtier comprising a plurality of substantially horizontal refrigerantconduits vertically spaced apart, a plurality of hollow, open ended airflow tubes, each said conduit having an air flow tube projecting throughthe interior of the conduit to define a thin, annular conduit space forthe passage of refrigerant in a thin annular layer through saidconduits, said air tubes being respectively of a length greater than thelength of the conduits related thereto and being positioned with theiropposite open ends extending outwardly beyond the ends of said conduits,said conduit ends being sealed to said air tubes, means connecting saidcirculating means with the uppermost conduit of said tier, meanssuccessively interconnecting adjacent conduits in said tier, plate meanslocated at the opposite side of said open housing end defining achamber, the open tube ends at one end of said tiers extending into saidchamber and the open tube ends at the opposite end of said tiersextending behind said wall means, for directing air flow through saidtubes, and

use

11 spirally twisted vanes mounted in said tubes for. imparting rotationto' air flow through said tubes, whereby to provide a tortuous pathwayfor a thin annular layer of refrigerant between relatively largeexternal and internal heat radiating surfaces subjected to the coolingeffect of said airflow.

10. Heat exchanger means adapted for use in a cooling system whichincludes means for" circulating a fluid refrigerant to and from saidheat exchanger means, a housing open at one end for air flow into saidhousing and having an air flow discharge from said housing, wall meanscutting ofi air flow through one side of said open end, and air flowimpeller means disposed to establish air flow in through said open endand out through said discharge; said heat exchanger means comprising aplurality of refrigerant conduits spaced apart and disposed in the pathof said air flow, a plurality of hollow, open ended air flow tubes, eachsaid conduit having an air flow tube projecting through the interior ofthe conduit to define a thin, annular conduit space for the passageduits, said air tubes being respectively of a length greater than thelength of the conduits related thereto and being positioned with theiropposite open ends extending outwardly beyond the ends of said conduits,each said air tube relative to its related conduit being inclined fromcontact with the upper portion of the conduit at one end to contact withthe lower portion of the conduit at the of refrigerant in a thin annularlayer through said conhaving a maximum lower space at one end and amaxi-' mum upper space at the other end, alternate conduits and tubes insaid tier being positioned with said tubes oppositely inclined, saidconduit ends being sealed to said air tubes, means connecting saidcirculating means with the uppermost conduit of said tier at the maximumupper space therein, means successively interconnecting the maximumspaces of adjacent conduits in said tier, plate means located at theopposite side of said open housing and defining a chamber, the open tubeends at oneend of said tiers extending into said chamber and the opentube ends at the opposite end of said tiers extending behind said wallmeans, for directing air flow through said tubes, whereby to provide atortuous pathway for a thin annular layer of refrigerant betweenrelatively large external and internal heat radiating surfaces subjectedto the cooling efifect of said air flow.

References Cited in the file of this patent UNITED STATES PATENTS1,005,442 Lovekin Oct. 10, 1911 1,132,420 Anderau Mar. 16, 19151,537,890 Seitz May 12, 1925 2,798,366 Erl July 9, 1957 2,806,674 BiehnSept. 17, 1957

